Composition of breast milk of lactating adolescents in function of time of lactation.

UNLABELLED The aim of this study was to evaluate the composition of breast milk of lactating adolescents in function of lactation time. METHODS We followed 51 lactating adolescents, between the 6th and 14th weeks postpartum (WPP). The determination of fat, protein and lactose in milk were conducted, respectively, by the methods of Lucas, Lowry and Perry & Doan. Micronutrients were determined by atomic absorption spectrophotometry. Data was presented by the mean and standard error. ANOVA with repeated measures was used and Tukey as post test. It was accepted a significance level of 5%. RESULTS There was a significant reduction (P<0.05) in protein content during the postpartum weeks studied (6th: 16.6 ± 1.1; 10th: 13.7 ± 1.0; 14th WPP: 12.3 ± 1.1 g/day). The lactose (6th: 60.2 ± 1.9; 10th: 60.4 ± 2.6; 14th WPP: 65.1 ± 4.0 g/day) and fat (6th: 41.6 ± 3.3; 10th: 36.2 ± 3.4; 14th WPP: 31.5 ± 9.0 g/day) concentration remained unaffected. The zinc concentration in the breast milk was lower than that is commonly found in literature (mean 1.16 mg/day). The copper, iron, calcium and phosphorus concentration was sufficient to meet the needs of the infants between 0 and 6 months old. CONCLUSION The lactation period did not influence the concentration of micronutrients, lactose and lipids, but there is a reduction on protein of the breast milk. In spite of the reducing concentration of protein, it is sufficient to meet the needs of infants from 0 to 6 months old.